CHF is associated with profound metabolic and neurohormonal disturbances. These may contribute to prolonged hospitalizations and readmission rates for exacerbations. In patients with CMF, diabetes and glycemic control are independent risk factors for mortality. Therefore, hospitalized patients with CHF exacerbation may be particularly suited for improved glycemic control. However, no studies have prospectively examined whether patients hospitalized with CHF would benefit from improved glucose control. The primary aims of this study are to determine whether early intravenous (IV) insulin therapy improves hospital length of stay and autonomic tone (assessed with heart rate variability [HRV], an independent predictor of mortality in patients with CHF. In secondary aims, the study will asses whether early IV insulin impacts other measures of autonomic tone (blood pressure variability [BPV] and catecholamine levels), physiologic parameters, such as plasma volume, cardiac index, and BNP, quality of life, and finally the effects on adiponectin isomers, which are important adipokines important for insulin sensitivity. In exploratory aims, the study will examine the effect of glycemic variability and whether any cost benefit is projected with early IV insulin. This protocol will be conducted among 240 patients admitted to the OSU Ross Heart Hospital service with decompensated heart failure due to systolic dysfunction (ejection fraction<35%). Patients will be randomly assigned to one of 2 groups: (1) early IV insulin therapy targeting a blood glucose of 101-150 mg/dL, or (2) a standardized physiologic subcutaneous insulin regimen. Intravenous insulin will be continued for a minimum of 72 hours, followed by transition to subcutaneous insulin. 30 days following discharge, patients will be contacted to determine disposition and to administer quality of life scores. Primary outcomes include hospital length of stay and HRV whereas secondary outcomes include BPV, catecholamine levels, cardiac index, plasma volume, BNP, quality of life scores, and adiponectin. RELEVANCE: Heart failure is a leading cause of mortality from diabetes and leads to prolonged hospital stays with frequent readmissions. Preliminary studies suggest that patients with worse diabetes control have higher mortality. The present study will address whether better early diabetes control improves hospital outcomes.